American alligator: alligator mississippiensis

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January 1998
U.S. Fish & Wildlife Service
American Alligator
Alligator mississippiensis
A member of the crocodile family, the
American alligator is a living fossil
from the Age of Reptiles, having
survived on earth for 200 million
years.
American alligator populations
reached all-time lows in the 1950s,
primarily due to market- hunting
and habitat loss. However, in 1987,
the alligator was pronounced fully
recovered, making it one of the first
endangered species success stories.
Today, alligators are found
throughout the Southeast, from
the Carolinas to Texas and north to
Arkansas.
Description and Diet
The alligator can be distinguished
from the crocodile by its head
shape and color. The crocodile has
a narrower snout, and unlike the
alligator, has lower jaw teeth that are
visible even when its mouth is shut.
In addition, adult alligators are black,
while crocodiles are brownish in color.
The alligator has a large, slightly
rounded body, with thick limbs, a
broad head, and a very powerful tail
that it uses to propel itself through
water. The tail accounts for half the
alligator’s length. While alligators
move very quickly in water, they
are generally slow-moving on land,
although they can be quick for short
distances.
Alligators will eat just about
anything, but primarily consume fish,
turtles, and snails. Small animals that
come to the water’s edge to drink
make easy prey. Young alligators
mostly feed on insects, crustaceans,
snails, and fish.
Biological Role
As during the Reptile Age, alligators
live in wetlands, vital habitat that
holds the key to their continued
survival. Alligators depend on
wetlands—and in some ways
wetlands depend on them. As
predators at the top of the food chain,
they help control numbers of rodents
and other animals that might overtax
the marshland vegetation.
The alligator’s greatest value to
the marsh and other animals within
it are the “gator holes” that many
adults create and expand through the
years. An alligator uses its mouth and
claws to uproot vegetation to clear
out a space; then, shoving with its
body and slashing with its powerful
tail, it wallows out a depression
that stays full of water in the wet
season and holds water after the
rains stop. During the dry season,
and particularly during extended
droughts, gator holes provide vital
water for fish, insects, crustaceans,
snakes, turtles, birds, and other
animals in addition to the alligator
itself.
Sometimes, the alligator may expand
its gator hole by digging beneath
an overhanging bank to create a
hidden den. After tunneling as
far as 20 feet, it enlarges the end,
making a chamber with a ceiling high
enough above water level to permit
breathing. This is not the alligator’s
nest but merely a place for the reptile
to survive the dry season and winter.
Breeding and Life History
The breeding season begins in the
spring. Although alligators have no
vocal cords, males bellow loudly to
attract mates and warn off other
males during this time by sucking air
into their lungs and blowing it out in
intermittent, deep-toned roars.
The female builds a nest of
vegetation, sticks, leaves, and mud
in a sheltered spot in or near the
water. After she lays 20 to 50 white,
goose-egg sized eggs, she covers
them under more vegetation, which,
like mulch, heats as it decays, helping
to keep the eggs warm. She remains
near the nest throughout the 65-
day incubation period, protecting
the nest from intruders. When the
American Alligator
John Hammond, USFWS
A combined effort by the U.S. Fish
and Wildlife Service and State
wildlife agencies in the South
saved these unique animals. The
Endangered Species Act prohibited
alligator hunting, allowing the species
to rebound in numbers in many areas
where it had been depleted. As it
began to make a comeback, States
established alligator monitoring
programs and used the information
to ensure that numbers continued
to increase. In 1987, the Fish and
Wildlife Service pronounced the
American alligator fully recovered
and consequently removed the animal
from the list of endangered species.
young begin to hatch, they emit a
high-pitched croaking noise, and the
female quickly digs them out. The
young, tiny replicas of adult alligators
with a series of yellow bands around
their bodies, then find their way to
water. For several days they continue
to live on yolk masses within their
bellies.
Alligators reach breeding maturity
between the ages of 8 and 13 years, at
which time they are about 6 to 7 feet
long. From then on, growth continues
at a slower rate. Old males may grow
to be 14 feet long and weigh up to
1,000 pounds during a lifespan of 30
years or more.
Decline and Recovery
Historically, alligators were depleted
from many parts of their range
as a result of market-hunting and
habitat loss. Forty years ago many
people believed this unique reptile
would never recover. In 1967, under
a law that preceded the Endangered
Species Act of 1973, the alligator was
listed as endangered, meaning it was
considered in danger of extinction
throughout all or a significant portion
of its range.
U.S. Fish and Wildlife Service
Endangered Species Program
4401 N. Fairfax Drive, Room 420
Arlington, VA 22203
703-358-2390
http://www.fws.gov/endangered/
U.S. Fish and Wildlife Service
Southeast Region
1875 Century Boulevard, N. E.
Atlanta, Georgia 30345
404-679-7100
http://www.fws.gov/southeast/
February 2008
Although the American alligator is
secure, some related animals—such
as several species of crocodiles and
caimans —are still in trouble. For
this reason, the Fish and Wildlife
Service continues to protect the
alligator under the ESA classification
as “threatened due to similarity
of appearance.” The Service thus
regulates the harvest of alligators
and legal trade in the animals, their
skins, and products made from them,
as part of efforts to prevent the illegal
take and trafficking of endangered
“look-alike” reptiles.
The story of the American alligator
is one of both drastic decline and
complete recovery. A story of State
and Federal cooperation, it is truly
one of the prominent successes of
the Nation’s endangered species
program.
(top): American alligator
(middle): Alligator hatching from the egg
(bottom): American alligator den
John Hammond, USFWS
USFWS
NPS

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January 1998
U.S. Fish & Wildlife Service
American Alligator
Alligator mississippiensis
A member of the crocodile family, the
American alligator is a living fossil
from the Age of Reptiles, having
survived on earth for 200 million
years.
American alligator populations
reached all-time lows in the 1950s,
primarily due to market- hunting
and habitat loss. However, in 1987,
the alligator was pronounced fully
recovered, making it one of the first
endangered species success stories.
Today, alligators are found
throughout the Southeast, from
the Carolinas to Texas and north to
Arkansas.
Description and Diet
The alligator can be distinguished
from the crocodile by its head
shape and color. The crocodile has
a narrower snout, and unlike the
alligator, has lower jaw teeth that are
visible even when its mouth is shut.
In addition, adult alligators are black,
while crocodiles are brownish in color.
The alligator has a large, slightly
rounded body, with thick limbs, a
broad head, and a very powerful tail
that it uses to propel itself through
water. The tail accounts for half the
alligator’s length. While alligators
move very quickly in water, they
are generally slow-moving on land,
although they can be quick for short
distances.
Alligators will eat just about
anything, but primarily consume fish,
turtles, and snails. Small animals that
come to the water’s edge to drink
make easy prey. Young alligators
mostly feed on insects, crustaceans,
snails, and fish.
Biological Role
As during the Reptile Age, alligators
live in wetlands, vital habitat that
holds the key to their continued
survival. Alligators depend on
wetlands—and in some ways
wetlands depend on them. As
predators at the top of the food chain,
they help control numbers of rodents
and other animals that might overtax
the marshland vegetation.
The alligator’s greatest value to
the marsh and other animals within
it are the “gator holes” that many
adults create and expand through the
years. An alligator uses its mouth and
claws to uproot vegetation to clear
out a space; then, shoving with its
body and slashing with its powerful
tail, it wallows out a depression
that stays full of water in the wet
season and holds water after the
rains stop. During the dry season,
and particularly during extended
droughts, gator holes provide vital
water for fish, insects, crustaceans,
snakes, turtles, birds, and other
animals in addition to the alligator
itself.
Sometimes, the alligator may expand
its gator hole by digging beneath
an overhanging bank to create a
hidden den. After tunneling as
far as 20 feet, it enlarges the end,
making a chamber with a ceiling high
enough above water level to permit
breathing. This is not the alligator’s
nest but merely a place for the reptile
to survive the dry season and winter.
Breeding and Life History
The breeding season begins in the
spring. Although alligators have no
vocal cords, males bellow loudly to
attract mates and warn off other
males during this time by sucking air
into their lungs and blowing it out in
intermittent, deep-toned roars.
The female builds a nest of
vegetation, sticks, leaves, and mud
in a sheltered spot in or near the
water. After she lays 20 to 50 white,
goose-egg sized eggs, she covers
them under more vegetation, which,
like mulch, heats as it decays, helping
to keep the eggs warm. She remains
near the nest throughout the 65-
day incubation period, protecting
the nest from intruders. When the
American Alligator
John Hammond, USFWS
A combined effort by the U.S. Fish
and Wildlife Service and State
wildlife agencies in the South
saved these unique animals. The
Endangered Species Act prohibited
alligator hunting, allowing the species
to rebound in numbers in many areas
where it had been depleted. As it
began to make a comeback, States
established alligator monitoring
programs and used the information
to ensure that numbers continued
to increase. In 1987, the Fish and
Wildlife Service pronounced the
American alligator fully recovered
and consequently removed the animal
from the list of endangered species.
young begin to hatch, they emit a
high-pitched croaking noise, and the
female quickly digs them out. The
young, tiny replicas of adult alligators
with a series of yellow bands around
their bodies, then find their way to
water. For several days they continue
to live on yolk masses within their
bellies.
Alligators reach breeding maturity
between the ages of 8 and 13 years, at
which time they are about 6 to 7 feet
long. From then on, growth continues
at a slower rate. Old males may grow
to be 14 feet long and weigh up to
1,000 pounds during a lifespan of 30
years or more.
Decline and Recovery
Historically, alligators were depleted
from many parts of their range
as a result of market-hunting and
habitat loss. Forty years ago many
people believed this unique reptile
would never recover. In 1967, under
a law that preceded the Endangered
Species Act of 1973, the alligator was
listed as endangered, meaning it was
considered in danger of extinction
throughout all or a significant portion
of its range.
U.S. Fish and Wildlife Service
Endangered Species Program
4401 N. Fairfax Drive, Room 420
Arlington, VA 22203
703-358-2390
http://www.fws.gov/endangered/
U.S. Fish and Wildlife Service
Southeast Region
1875 Century Boulevard, N. E.
Atlanta, Georgia 30345
404-679-7100
http://www.fws.gov/southeast/
February 2008
Although the American alligator is
secure, some related animals—such
as several species of crocodiles and
caimans —are still in trouble. For
this reason, the Fish and Wildlife
Service continues to protect the
alligator under the ESA classification
as “threatened due to similarity
of appearance.” The Service thus
regulates the harvest of alligators
and legal trade in the animals, their
skins, and products made from them,
as part of efforts to prevent the illegal
take and trafficking of endangered
“look-alike” reptiles.
The story of the American alligator
is one of both drastic decline and
complete recovery. A story of State
and Federal cooperation, it is truly
one of the prominent successes of
the Nation’s endangered species
program.
(top): American alligator
(middle): Alligator hatching from the egg
(bottom): American alligator den
John Hammond, USFWS
USFWS
NPS